<?php

namespace GetId3\Module\Audio;

use GetId3\Handler\BaseHandler;
use GetId3\Lib\Helper;

/////////////////////////////////////////////////////////////////
/// GetId3() by James Heinrich <info@getid3.org>               //
//  available at http://getid3.sourceforge.net                 //
//            or http://www.getid3.org                         //
/////////////////////////////////////////////////////////////////
// See readme.txt for more details                             //
/////////////////////////////////////////////////////////////////
//                                                             //
// module.audio.dss.php                                        //
// module for analyzing Digital Speech Standard (DSS) files    //
// dependencies: NONE                                          //
//                                                            ///
/////////////////////////////////////////////////////////////////

/**
 * module for analyzing Digital Speech Standard (DSS) files
 *
 * @author James Heinrich <info@getid3.org>
 *
 * @link http://getid3.sourceforge.net
 * @link http://www.getid3.org
 */
class Dss extends BaseHandler
{
    /**
     * @return bool
     */
    public function analyze()
    {
        $info = &$this->getid3->info;

        fseek($this->getid3->fp, $info['avdataoffset'], SEEK_SET);
        $DSSheader = fread($this->getid3->fp, 1256);

        if (!preg_match('#^(\x02|\x03)dss#', $DSSheader)) {
            $info['error'][] = 'Expecting "[02-03] 64 73 73" at offset '.$info['avdataoffset'].', found "'.Helper::PrintHexBytes(substr($DSSheader, 0, 4)).'"';

            return false;
        }

        // some structure information taken from http://cpansearch.perl.org/src/RGIBSON/Audio-DSS-0.02/lib/Audio/DSS.pm

        // shortcut
        $info['dss'] = array();
        $thisfile_dss = &$info['dss'];

        $info['fileformat'] = 'dss';
        $info['audio']['dataformat'] = 'dss';
        $info['audio']['bitrate_mode'] = 'cbr';
        //$thisfile_dss['encoding']              = 'ISO-8859-1';

        $thisfile_dss['version'] = ord(substr($DSSheader, 0, 1));
        $thisfile_dss['date_create'] = self::DSSdateStringToUnixDate(substr($DSSheader, 38, 12));
        $thisfile_dss['date_complete'] = self::DSSdateStringToUnixDate(substr($DSSheader, 50, 12));
        //$thisfile_dss['length']         =                         intval(substr($DSSheader,  62,   6)); // I thought time was in seconds, it's actually HHMMSS
        $thisfile_dss['length'] = intval((substr($DSSheader, 62, 2) * 3600) + (substr($DSSheader, 64, 2) * 60) + substr($DSSheader, 66, 2));
        $thisfile_dss['priority'] = ord(substr($DSSheader, 793, 1));
        $thisfile_dss['comments'] = trim(substr($DSSheader, 798, 100));

        //$info['audio']['bits_per_sample']  = ?;
        //$info['audio']['sample_rate']      = ?;
        $info['audio']['channels'] = 1;

        $info['playtime_seconds'] = $thisfile_dss['length'];
        $info['audio']['bitrate'] = ($info['filesize'] * 8) / $info['playtime_seconds'];

        return true;
    }

    /**
     * @param  type $datestring
     *
     * @return type
     */
    protected static function DSSdateStringToUnixDate($datestring)
    {
        $y = substr($datestring, 0, 2);
        $m = substr($datestring, 2, 2);
        $d = substr($datestring, 4, 2);
        $h = substr($datestring, 6, 2);
        $i = substr($datestring, 8, 2);
        $s = substr($datestring, 10, 2);
        $y += (($y < 95) ? 2000 : 1900);

        return mktime($h, $i, $s, $m, $d, $y);
    }
}
